This section provides background information related to the present disclosure, which is not necessarily prior art.
With reference to prior art FIG. 1, heating, ventilation, and air conditioning (HVAC) systems typically include an actuator 12 (i.e., actuator motor/DC motor), which turns an axle or shaft 50. The axle 50 rotates a gear train 28. Connected to the gear train 28 is an HVAC airflow control door 22, which is moved to control airflow. The actuator 12 generates current pulse waveforms as the actuator 12 rotates the axle 50. The number of current pulse waveforms generated corresponds to how much the axle 50 has rotated. Thus by counting the number of current pulse waveforms generated, a climate control module of the HVAC system is able to determine how much the axle 50 has rotated, and how far airflow control door 22 coupled to the axle 50 has moved in order to determine the position of the airflow control door 22.
While existing HVAC actuators are suitable for their intended use, they are subject to improvement. For example, existing HVAC actuators generate inconsistent current pulse waveforms that are difficult for climate control modules to regularly detect. As a result, one or more current pulse waveforms often go undetected, which results in the climate control module being unable to accurately determine the actual position of the airflow control door, and typically leads to the climate control module generating a diagnostic trouble code.
Prior art FIG. 2 illustrates a plurality of current pulse waveforms 10A-10F generated by existing actuators. The current pulse waveforms 10A-10F are inconsistent in at least their shape (i.e., voltage), which makes it difficult for a climate control module to detect the waveforms 10A-10F. It would therefore be desirable to have an airflow control door that generates current pulse waveforms that can be detected by a climate control module on a consistent basis so that the climate control module will be able to determine position of the airflow control door more precisely. The present teachings successfully overcome these issues in the art, as well as numerous others.